Webhooks

The platform captures upstream activity events and exposes them as a polling API, so you do not stand up your own receiver.

You do not register a callback URL. Instead you query the latest known state of a product, product-type, or booking. Send SessionId as a query parameter.

Read the latest event

GET/Activity/v2/webhook-events/{event}/{uuid}

Access requires the permission activity_webhook_events

Pass the event name and the entity uuid. You get the most recent event of that type for that entity.

Event types

Event	Fires when
`product_available`	A product becomes available.
`product_updated`	A product's content changes.
`product_type_available`	A variant becomes available.
`product_type_not_available`	A variant becomes unavailable.
`product_type_content_updated`	A variant's content changes.
`product_type_pricing_updated`	A variant's price changes.
`product_type_availability_updated`	A variant's availability changes.
`booking_status_updated`	A booking's status changes.
`booking_data_updated`	A booking's data changes.
`booking_tickets_updated`	A booking's tickets change.

Query parameters

Name	Type	Required	Default	Description
`history`	boolean	No	`false`	Return a list of past events instead of the latest one.
`limit`	integer	No	`20`	History size, 1 to 50. Presence of `limit` turns on history mode.

curl "https://api.hermeseus.com/api/Activity/v2/webhook-events/booking_status_updated/1d59a17e-9726-4283-a5b7-bab7886e4709?SessionId=8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f"

const uuid = "1d59a17e-9726-4283-a5b7-bab7886e4709";
const res = await fetch(`https://api.hermeseus.com/api/Activity/v2/webhook-events/booking_status_updated/${uuid}?SessionId=8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f`);
const data = await res.json();

import requests

uuid = "1d59a17e-9726-4283-a5b7-bab7886e4709"
res = requests.get(
    f"https://api.hermeseus.com/api/Activity/v2/webhook-events/booking_status_updated/{uuid}",
    params={"SessionId": "8f3c81d2-4a5b-4c6d-9e0f-1a2b3c4d5e6f"},
)

data = res.json()

Response

Latest mode returns the newest event, or found: false when there is none.

{
  "event": "booking_status_updated",
  "primaryUuid": "1d59a17e-9726-4283-a5b7-bab7886e4709",
  "found": true,
  "id": 55213,
  "receivedAt": "2026-10-14T11:02:03.000+08:00",
  "eventTimestamp": "2026-10-14T11:02:00.000+08:00",
  "payload": { "currentStatus": "APPROVED" }
}

History mode returns count and an items array of the same objects.

Do not poll in a tight loop. Poll on a sensible interval, or check the event right after an action that would change it. For booking issuance, read booking_status_updated instead of re-fetching the booking repeatedly.